Searcharxiv⌕ Search

arXiv subjects

Piotr Antoni Kołaczek-Szymański

Publications and source records attributed to Piotr Antoni Kołaczek-Szymański.

3 recordsLinked to original sources

HD3191, the high-mass X-ray binary that wasn't there

The rapidly rotating B1 IV:nn star HD3191 lies within the error box of a flaring Fermi gamma-ray source. Although the counterpart of the Fermi source is likely an active galaxy, HD3191 has nevertheless been suggested to be a high-mass X-ray binary, possibly hosting a black hole companion. The star displays roughly sinusoidal photometric variations with amplitudes of about 12 mmag for two frequencies $ν_1$ = 0.1235 d$^{-1}$ and $ν_2$ = 1.6038 d$^{-1}$. Half of the former frequency ($ν_1$/2) had previously been interpreted as the orbital frequency of a high-mass X-ray binary in which the B1 IV:nn primary undergoes ellipsoidal variations. We show that this scenario fails to account for the lack of significant radial velocity variations and for the overall properties of the star. Our spectroscopic observations instead unveil line profile variations, suggesting that the photometric and line profile variations arise from multi-mode pulsations rather than from orbital effects. Whilst we cannot rule out the possibility that HD3191 could be a nascent binary, consisting of a B1 IV:nn with a low-mass pre-main sequence companion, the most likely scenario is a single star displaying non-radial pulsations. The fast stellar rotation would thus be intrinsic to the B1 IV:nn star rather than being the result of a spin-up during a past mass-transfer episode.

astro-ph.HE↗

Exploring extreme brightness variations in blue supergiant MACHO 80.7443.1718: Evidence for companion-driven enhanced mass loss

Evolution of massive stars is dominated by interactions within binary systems. Therefore, it is necessary to investigate all forms of interaction in binary systems that may affect the evolution of the components. One of such laboratories is the massive eccentric binary system MACHO$\,$80.7443.1718 (ExtEV). We examine whether the light variability of the ExtEV can be explained by a wind-wind collision (WWC) binary system model. We conducted an analysis of broadband multi-color photometry of ExtEV, time-series space photometry from TESS, ground-based Johnson $UBV$ photometry, and time-series spectroscopy. We fitted an analytical model of light variations to the TESS light curve of ExtEV. We rule out the possibility of the presence of a disk around the primary component. We also argue that the non-linear wave-breaking scenario may not be consistent with the observations of ExtEV. We refine the orbital parameters of ExtEV and find evidence for the presence of a tertiary component. Using evolutionary models we demonstrate that the primary component's mass is between 25 and 45$\,$M$_\odot$. We successfully reproduce light curve of ExtEV with our model, showing that the dominant processes shaping its light curve are atmospheric eclipse and light scattered in the WWC cone. We also estimate the primary's mass-loss rate due to stellar wind for $4.5\cdot 10^{-5}\,$M$_\odot\,{\rm yr}^{-1}$. We conclude that ExtEV is not an extreme eccentric ellipsoidal variable, but an exceptional WWC binary system. The mass loss rate we derived exceeds theoretical predictions by up to two orders of magnitude. This implies that the wind is likely enhanced by tidal interactions, rotation, and possibly also tidally excited oscillations. ExtEV represents a rare evolutionary phase of a binary system that may help to understand the role of a companion-driven enhanced mass loss in the evolution of massive binary systems.

astro-ph.SR↗

Massive heartbeat stars from TESS. I. TESS sectors 1-16

Heartbeat stars are eccentric binaries exhibiting characteristic shape of brightness changes during periastron passage caused by tidal distortion of the components. Variable tidal potential can drive tidally excited oscillations (TEOs), which are usually gravity modes. Studies of heartbeat stars and TEOs open a new possibility to probe interiors of massive stars. There are only a few massive (masses of components $\gtrsim 2 $M$_\odot$) systems of this type known. Using TESS data from the first 16 sectors, we searched for new massive heartbeat stars and TEOs using a sample of over 300 eccentric spectroscopic binaries. We analysed TESS 2-min and 30-min cadence data. Then, we fitted Kumar's analytical model to the light curves of stars showing heartbeats and performed times-series analysis of the residuals searching for TEOs and periodic intrinsic variability. We found 20 massive heartbeat systems, of which seven show TEOs. The TEOs occur at harmonics of orbital frequencies in the range between 3 and 36, with the median value equal to 9, lower than those in known Kepler systems with TEOs. The most massive system in this sample is the quadruple star HD 5980, a member of Small Magellanic Cloud. With the total mass of $\sim$150 M$_{\odot}$ it is the most massive system showing a heartbeat. Six stars in the sample of the new heartbeat stars are eclipsing. Comparison of the parameters derived from fitting Kumar's model and from light-curve modelling shows that Kumar's model does not provide reliable parameters. Finally, intrinsic pulsations of $β$ Cep, SPB, $δ$ Sct, and $γ$ Dor-type were found in nine heartbeat systems. This opens an interesting possibility of studies of pulsation-binarity interaction and the co-existence of forced and self-excited oscillations.

astro-ph.SR↗